1. Field of the Invention
The invention is related to the field of communication networks, and in particular, to networks and methods for implementing the feature of repeat dialing in wireless networks to called parties that are powered off.
2. Statement of the Problem
Telephone service providers offer many features to service subscribers. One feature offered to traditional wireline subscribers is repeat dialing of busy numbers. Assume a caller places a call to a dialed number. Within the telephone network, an originating switch receives the call and routes the call to a terminating switch for the dialed number. The terminating switch determines that the circuit for that dialed number is busy, and responds to the originating switch that the dialed number is busy. The originating switch plays busy tones to the caller. When the caller hears the busy tones, the caller hangs up the telephone. The caller then picks up the receiver on the telephone and enters a code, such as *66, into the telephone to activate the repeat dialing feature to the last-dialed number. The caller can then hang up the telephone go about other business. The telephone network attempts to set up a call to the dialed number when the dialed number becomes available.
Within the telephone network, the originating switch receives the code entered by the caller. The originating switch informs the terminating switch that repeat dialing has been activated for the dialed number. When the circuit for the dialed number becomes available, the terminating switch identifies that repeat dialing has been activated for the dialed number. The terminating switch then attempts to set up a call from the caller to the dialed number. The caller may receive a special tone indicating that the dialed number is now available.
One problem with the current repeat dialing feature is that the feature is only effectively implemented and offered for wire line telephone networks. The repeat dialing feature is not currently offered for cellular networks or other wireless networks. Also, the repeat dialing is only offered for busy numbers. Wireless networks present an additional issue that mobile phones may be powered off. When a mobile phone is powered off, calls to that mobile phone will go unanswered and most likely routed to voice mail. A problem exists that a repeat dialing feature to powered-off mobile phones is not currently offered. With the large number of mobile subscribers, wireless service providers are missing out on large revenues by not offering the repeat dialing feature.